fix: 密码重置链路断裂与店铺模板类型不兼容

删除 users-api 的 forgot-password 空壳路由，email-api 的
forgotPasswordLogic 复用 sendVerificationCode 实现。shop 的
UpdateTemplateReq.Sections 从 interface{} 改为 string 以兼容
go-zero 反序列化。ResetPasswordReq.Phone 加 optional tag。

app/email/api/internal/logic/email/forgotPasswordLogic.go

@@ -27,8 +27,9 @@ func NewForgotPasswordLogic(ctx context.Context, svcCtx *svc.ServiceContext) *Fo
 	}
 }
 
-func (l *ForgotPasswordLogic) ForgotPassword(req *types.ForgotPasswordReq) (resp *types.EmptyResp, err error) {
-	// todo: add your logic here and delete this line
-
-	return
+func (l *ForgotPasswordLogic) ForgotPassword(req *types.ForgotPasswordReq) (resp *types.SendVerificationCodeResp, err error) {
+	return NewSendVerificationCodeLogic(l.ctx, l.svcCtx).SendVerificationCode(&types.SendVerificationCodeReq{
+		Email: req.Email,
+		Scene: "reset_password",
+	})
 }